Centrifugal separator

ABSTRACT

A centrifugal separator for a liquid containing undesirable heavier materials, including: a generally vertical outer housing providing a generally vertical axis; a rotary casing mounted for rotation in the housing in a predetermined direction about such axis; a radially central inlet in the lower side of the casing and a radially central outlet in the upper side thereof; inlet means for delivering a liquid containing undesirable heavier materials to the inlet from the interior of the housing and including an axial flow pump driven by the casing; means for delivering a liquid to be cleaned to the housing and for maintaining the liquid level in the housing within a predetermined range above the inlet means; outlet means carried by and leading to the exterior of the housing and communicating with the outlet for receiving cleaned liquid; an axially central partition in the casing perpendicular to the axis and separating the inlet and the outlet, the outer periphery of the partition being spaced radially inwardly from the inner periphery of the casing; radial baffles in the casing on both sides of the partition and extending axially from the partition to the respective sides of the casing, the baffles extending radially from central regions of the casing to the inner periphery thereof to divide the casing into circumferentially spaced compartments, and the radial baffles being of different radial lengths; passage means in the peripheral wall of the casing and communicating with the compartments and the housing externally of the casing, such passage means being of a size to permit passage of heavier particles in the liquid, and some of the liquid, outwardly into the housing while causing at least a substantial portion of the liquid to be discharged from the casing through the outlet; and a sludge and excess liquid drain at the bottom of the housing. The passage means includes: an annular collecting chamber in the peripheral wall of the casing between the inner and outer peripheries thereof; orifices respectively connecting the compartment to the collecting chamber and extending generally rearwardly from the compartment to the collecting chamber with respect to the direction of rotation of the casing; and tangential nozzles carried by the casing on the outer periphery thereof and facing rearwardly relative to the direction of rotation of the casing and communicating with the collecting chamber. With this construction, the orifices and the nozzles assist the drive means for the rotary casing in driving the casing in the desired direction.

2 tea atertt 1 tlnitle lErilrson et a1.

[ CENTRIIFUGAL SEPARATUR [75] Inventors: John W. Eriltsen, Huntington Beach; Vitolis Budrys, La Mirada, both of Calif.

[73] Assignee: Kobe, inc, Huntington Park, Calif.

[22] Filed: June 4, 1973 [21] Appl. No; 366,442

[52] US. Cl. 233/32,233/47 R [51] llnt. Cl B041) 11/112 [58] Field of Search 233/3, 7, 19 R, 27, 28, 233/30, 32, 33, 44, 16, 29, 14 R, 46, 47 R [56] 7 References Cited UNITED STATES PATENTS 943,083 12/1909 Kuchs 233/28 X 980,001 12/1910 Ponten 233/3 X 1,154,575 9/1915 MeCallum 233/7 X 2,743,865 5/1956 Graae 233/7 3,125,516 3/1964 Kaldewey 233/29 X 3,768,726 10/1973 Hale et al. 233/16 3,774,840 11/1973 Boatright 1. 233/14 R FOREIGN PATENTS OR APPLlCATlONS 362,652 7/1962 Switzerland 233/3 Primary Examiner-George H. Krizmanich Attorney, Agent, or Firm-Harris, Kern, Wallen & Tinsley [5 7] ABSTRACT A centrifugal separator for a liquid containing undesirable heavier materials, including: a generally vertical outer housing providing a generally vertical axis; a rotary casing mounted for rotation in the housing in a predetermined direction about such axis; a radially central inlet in the lower side of the casing and a radially central outlet in the upper side thereof; inlet means for delivering a liquid containing undesirable heavier materials to the inlet from the interior of the housing and including an axial flow pump driven by the casing; means for delivering a liquid to be cleaned to the housing and formaintaining the liquid level in the housing within a predetermined range above the inlet means; outlet means carried by and leading to the exterior of the housing and communicating with the outlet for receiving cleaned liquid; an axially central partition in the casing perpendicular to the axis and separating the inlet and the outlet, the outer periphery of the partition being spaced radially inwardly from the inner periphery of the casing; radial baflles in the casing on both sides of the partition and extending axially from the partition to the respective sides of the casing, the baffles extending radially from central regions of the casing to the inner periphery thereof to divide the easing into circumferentially spaced cornpartments, and the radial baffles being of different radial lengths; passage means in the peripheral wall of the casing and communicating with the compartments and the housing externally of the casing, such passage means being of a size to permit passage of heavier particles in the liquid, and some of the liquid, outwardly into the housing while causing at. least a substantial portion of the liquid to be discharged from the casing through the outlet; and a sludge and excess liquid drain at the bottom of the housing. The passage means includes: an annular collecting chamber in the peripheral wall of the casing between the inner and outer peripheries thereof; orifices respectively connecting the compartment to the collecting chamber and extending generally rearwardly from the compartment to the col lecting chamber with respect to the direction of rotation of the casing; and tangential nozzles carried by the casing on the outer periphery thereof and facing rearwardly relative to the direction of rotation of the casing and communicating with the collecting chamber. With this construction, the orifices and the nozzles assist the drive means for the rotary casing in driving the casing in the desired direction.

4 Claims, 5 Drawing lt igures CIENTIRIFUGAL SEPARATOIR CROSS REFERENCE TO RELATED APPLICATION This application discloses and claims subject matter disclosed in our co-pending patent application Ser. No. 321,709 on Pitot Pump With Centrifugal Separator, filed Jan. 8, 1973.

BACKGROUND OF INVENTION The present invention relates in general to a centrifu- SUMMARY AND OBJECTS OF INVENTION A general object of the invention is to provide a centrifugal separator which will handle a large volume of liquid efficiently and which will remove heavier contaminants therefrom effectively.

More particularly, the invention may be summarized as including, and an important object is to provide a centrifugal separator which includes, an outer housing providing an axis; a rotary casing mounted for rotation in the housing in a predetermined direction about such axis; a radially central inlet and a radially central outlet in the casing; inlet means for delivering a liquid containing undesirable heavier materials to the inlet; outlet means carried by and leading to the exterior of the housing and communicating with the outlet for receiving cleaned liquid; baffles in the casing and dividing the casing into circumferentially spaced compartments; and passage means in the peripheral wall of the casing and communicating with the compartments and the housing externally of the casing, the passage means being of a size to permit passage of heavier particles in the liquid, and some of the liquid, outwardly into the housing while causing at least a substantial portion of the liquid to be discharged as clean liquid from the easing through the outlet.

The invention may be further summarized as including, and another important object is to provide a centrifugal separator which includes: an outer housing providing an axis; a rotary casing mounted for rotation in the housing in a predetermined direction about the axis; a radially central inlet in one side of the casingand a radialy central-outlet in the other; inlet means in the housing for delivering a liquid containing undesirable heavier materials to the inlet; outlet means carried by and leading to the exterior of the housing and communicating with the outlet for receiving cleaned liquid; an axially central partition in the casing perpendicular to the axis and separating the inlet and the outlet, with the outer periphery of the partition being spaced radially inwardly from the inner periphery of the casing; radial baffles in the casing on both sides of the partition and extending axially from the partition to the respective sides of the casing,the baffles also extending radially from central regions of the casing to the inner periphery thereof to divide the casing into circumferentially spaced compartments; and passage means communicating with the compartments and the housing externally of the casing, the passage means being of a size to permit passage of heavier particles in the liquid. and some of the liquid, outwardly into the housing while causing at least a substantial portion of the liquid to be discharged from the casing through the outlet as cleaned liquid.

The invention may be still further summarized as in cluding, and a still further important object of the invention is to provide a centrifugal separator of the fore going nature which includes: an annular collecting chamber in the peripheral wall of the casing between the inner and outer peripheries thereof; orifices respectively connecting the compartments to the collecting chamber and of a size to permit heavier particles in the liquid, and some of the liquid, to pass outwardly into the collecting chamber without a. substantial pressure loss, the orifices being inclined generally rearwardly from the compartment to the collecting chamber with respect to the direction of the rotation of the casing; and tangential nozzles carried by the casing on the outer periphery thereof and facing rearwardly relative to the direction of rotation of the casing and communicating with the collecting chamber to discharge contaminants and some of the liquid therefrom.

With the foregoing construction, the rearward, tangential discharge of some of the liquid and the contaminants into the housing assists the means employed for driving the casing, thereby reducing the power require ments of the installation, which is an important feature.

sludge and excess liquid drain at the bottom of thehousing and a gas outlet at the top thereof.

A further object of the invention is to provide a cen trifugal separator wherein the inlet means communicates with the housing above the bottom thereof, is coaxial with and connected to and driven by the rotary casing, and includes an axial flow pump for delivering the liquid to be cleaned from the housing to the inlet of the rotary casing.

Yet another object is to provide a centrifugal separator including means for delivering a liquid to be cleaned to the housing, and means for maintaining the liquid level in the housing within a predetermined range above the lower end of the inlet means.

Theforegoing objects, advantages, features and results of the present invention, together with various other objects, advantages, features and results thereof which will be evident to those skilled in the centrifugal separator art in the light of this disclosure, may be achieved with the exemplary embodiment of the invention illustrated in the accompanying drawings and described in detail hereinafter.

DESCRIPTION OF DRAWINGS In the drawings: FIG. I is a vertical sectional view of a centrifugal separator which embodies the invention;

FIG. 2 is an enlarged, fragmentary vertical sectional view of a rotary casing within an outer housing and forming part of the centrifugal separator;

DESCRIPTION OF EXEMPLARY EMBODIMENT OF THE INVENTION In the drawings, the centrifugal separator of the invention is designated generally by the numeral .10 and includes a generally cylindrical, upright outer housing 12 having a downwardlyconvergent lower end 14 and supported by suitable legs 16. The outer housing 12 is provided in-the side wall thereof with an inlet means 18 for a fluidto be cleaned, such as, crude oil containing gas and contaminants, such as water, solid particles, and the like. The inlet means 18 includes a baffiesystem 20 for directing the inlet flow downwardly and laterally of the outer housing 12.

The downwardly convergent lower end 14 of the outer housing 12 is provided at its apex with a drain 22 for excess liquid and for sludge removed in the centrifugal separator 10. Upper and lower liquid level controls 24 and 26 maintain the liquid level within a'predetermined range by controlling the admission of fluid through the inlet means 18 and/or the discharge of liquid through the drain 22, in a manner not specifically shown, but well known in the art.

The outer housing 12 is provided at its upper end with a gas outlet 28 leading to a suitable point of gas disposal. Also provided at the upper end of the outer housing 12 is an outlet means 30 for cleaned liquid,

leading to a suitable point of storage or use of such liquid.

Within the outer housing 12 adjacent the upper end thereof is a rotary casing which is rotatable about the generally vertical axis of the outer housing. More particularly,-the rotary casing 40 is carried by a generally vertical shaft' 42 mounted in suitable bearings which need not be described specifically. The rotary casing 40 is driven in a predetermined direction by a motor 44, preferably an electric motor, surmounting the outer housing and connected to the upper end of the shaft 42.

The rotary casing 40 is provided in its lower end or side with a radially central or axial inlet 46 for the liquid to be cleaned. The inlet 46 communicates with the interior of the outer housing I2 through a depending inlet means 48 the lower end of which is below the liquid level maintained within the predetermined range by the level controls 24 and 26. More particularly, the

- inlet means 48 comprises a depending tube 50 which is The rotary casing 40 is provided in its upper end or side in a radially central, interrupted annular outlet 58 which, as clearly shown in FIG. 3, communicates with the liquid outlet means 30 for cleaned liquid.

The rotary casing 40 includes a substantially axially central partition 60 perpendicular to the axis of rotation and separating the outlet 58 from the inlet 46, the outer periphery of the partition being spaced radially inwardly from the inner periphery of the casing itself, as best shown in FIG. 3 of the drawings. The rotary casing 40 further includes circumferentially spaced, radially extending baffles 62, 64, 66 and 68 on both sides of the partition 60, such baffles extending axially from the partition to the respective upper and lower sides of the rotary casing. The baffles 62, 64, 66 and 68 arc of different radial lengths and extend radially outwardly from respective central regions of the rotary casing 40 to the inner periphery thereof to divide the rotary casing into circumferentially spaced compartments 70.

The peripheral wall of the rotary casing 12 is provided therethrough with passage means 72 communicating with the compartments 70 and the outer housing 12 externally of the rotary casing, such passage means being of a size to permit passage of heavier particles in the liquid, and some of the liquid, outwardly into the outer housing, and causing at least a substantial portion of the liquid, and preferably a major portion thereof, to be discharged from the rotary casing through its outlet 58 and the clean liquid outlet means 30.

The passage means designated generally as 72 includes an annular collecting chamber 74 in the peripheral wall of the rotary casing between the inner and outer peripheries thereof, as best shown in FIGS. 3 and 4. Orifices 76 interconnect the respective compartments'70 and the annular collecting chamber 74, such orifices extending generally. rearwardly' from the respective compartments relative to the direction of rotationof the casing. With this construction, the semitangential flow through the orifices 76 produces circumferential flow in the annular collecting chamber 74 to prevent a build up of solids therein. The orifices 76 are of a size to pass heavier particles in the liquid being cleaned, and some of the liquid, as hereinbefore discussed.

In addition, the passage means 72 include circumferentially spaced tangential nozzles 80 carried by the rotary casing 40 on the outer periphery thereof, only one such nozzle being visible in FIGS. 3 and 6. Each of these nozzles 80 communicates with the annular collecting chamber 74 through passages 82 and 84, FIG. 6, and is directed rearwardly with respect to the direction of rotation of the rotary casing 40 so that the liquid discharge therefrom also assists the motor 44 in driving the rotary casing. This materially reduces the power requirements of the motor 44, which is an important feature. The orifices 76 are preferably rectangular in cross section and typically may comprise a rectangular groove formed in the mating face of the two rotary casing sections shown in FIG. 3, such sections being suitably bolted, or otherwise secured, together.- The nozzles 80, as best shown in FIG. 6, are provided with sharp edged orifices 86 which are preferably of circular cross section. I

In operation, the liquid to be cleaned flows radially outwardly into the compartments from the inlet 46, and then radially inwardly through such compartments to the outlet 58, as indicated by the arrows 88 in FIG. 3 of the drawings. The flow paths represented by the arrows 88 insures that heavier particles are maintained adjacent the inner periphery of the rotary casing 40 long enough to insure removal of most of them by way of the orifices '76, the collecting chamber '74, the passages 82 and 04, and the nozzles 80. Further, the baffles 62, 6d, 66, and 63, in cooperation with the partition 60, prevent any possibility of short circuiting of heavier particles from the inlet 46 to the outlet 58. Another advantage of the baffles 62, 64, 66 and 68 is that they serve to accelerate the liquid to the speed of the rotary casing 40 promptly, so that there is no slippage of the rotary casing relative to the incoming liquid to be cleaned.

For cleaning crude oil containing such contaminants as water, solid particles and the like, the orifices or slots 76 may typically be of the order of 0.005 inch by 0.100

inch in cross section and each nozzle orifice 86 may i have a diameter of the order of 0.020 inch. With this dimensional relationship, the slots '76 serve as strainers, and, since most of the solid particles are approximately round, a particle larger than 0.005 inch cannot pass through the screen slots 76, thereby preventing nozzle plugging since the nozzle diameter is greater than 0.005 inch.

The size of the orifices 86 in the nozzle is made small so as to prevent any substantial loss of fluid during operation. Also, the total cross sectional area of the slots '76 is made larger than the total cross sectional area of the nozzle orifices 86, at least by a factor of two to one and preferably by a factor of three to one. This size ratio is controlled by the sizes of the slots '76 and the nozzle orifices 86 and by the respective numbers thereof. With this size relationship, the pressure drop through the strainer section is small compared to the pressure drop through the nozzles 80, being in the order of one to nine for the area ratio of three to one. With this configuration, efficiency is not greatly affected by the removal of heavy materials. The major portion of the velocity head which would be lost through the separating operation is regained by the jet effect of the liquid exhausting through the nozzles 80, which is an important feature.

it is thought that the over-all operation of the invention will be clear from the foregoing so that no further explanation is required.

Although an exemplary embodiment of the invention has been disclosed for illustrative purposes, it will be understood that various changes, modifications and substitutions may be incorporated in such embodiment without departing from the spirit of the invention as defined by the claims appearing hereinafter.

We claim as our invention:

ll. In a centrifugal separator for a liquid containing undesirable heavier materials the combination of:

a. an outer housing providing an axis;

b. a rotary casing mounted for rotation in said housing in a predetermined direction about said axis;

c. said casing having a radially central inlet and a radially central outlet;

d. inlet means for delivering a liquid containing undesirable heavier materials to said inlet;

e. outlet means carried by and leading to the exterior of said housing and communicating with said outlet for receiving cleaned liquid;

f. baffles in said casing and dividing said casing into circumferentially spaced compartments; and

g. the peripheral wall of said casing having passage means communicating with said compartments and said housing of a size to permit passage of heavier particles in theliquid, and some of the liquid, outwardly into said housing while causing at least a substantial portion of the liquid to be discharged from said casing through said outlet, said passage means including an annular collecting chamber in said peripheral wall of said casing between the inner and outer peripheries thereof, orifices respectively connecting said compartments to said collecting chamber, and tangential nozzles carried by said casing on the outer periphery thereof and facing rearwardly relative to the direction of rotation of said casing and communicating with said collecting chamber, said orifices extending generally rearwardly from said compartments to said collecting chamber with respect to the direction of rotation of said casing.

2. In a centrifugal separator for a liquid containing undesirable heavier materials, the combination of:

a. an outer housing providing an axis;

b. a rotary casing mounted for rotation in said housing in a predetermined direction about said axis; c. said casing having a radially central inlet in one side thereof and a radially central outlet in the other;

(1. inlet means in said housing for delivering a liquid containing undesirable heavier materials to said inlet;

e. outlet means carried by and leading to the exterior of said housing and communicating with said outlet for receiving cleaned liquid;

f. a substantially axially central partition in said casing perpendicular to said axis and separating said inlet and saidoutlet;

g. the. outer periphery of said partition being spaced radially inwardly from the inner periphery of said casing;

h. radial baffles in said casing on both sides of said partition and extending axially from said partition to the respective sides of said casing;

i. said baffles extending radially from central regions of said casing to the inner periphery thereof to divide said casing into circumferentially spaced compartments; and

j. the peripheral wall of said casing having passage means communicating with said compartments and said housing of a size to permit passage of heavier particles in the liquid, and some of the liquid, outwardly into said housing while causing at least a substantial portion of the liquid to be discharged from said casing through said outlet, said passage means including an annular collecting chamber in said peripheral wall of said casing between the inner and outer peripheries thereof, orifices respectively connecting said compartment to said collecting chamber, and tangential nozzles carried by said casing on the outer periphery thereof and facing rearwardly relative to the direction of rotation of said casing and communicating with said collecting chamber, said orifices extending generally rearwardly from said compartments to said collecting chamber with respect to the direction of rotation of said casing.

3. A centrifugal separator as :set forth in claim 2 wherein thesmallest transverse dimension of said orifices is less than the smallest transverse dimension of said nozzles.

4i. A centrifugal separator according to claim 3 wherein the total cross sectional area of said orifices exceeds the total cross sectional area of said nozzles by a ratio of the order of at least two to one. 

1. In a centrifugal separator for a liquid containing undesirable heavier materials the combination of: a. an outer housing providing an axis; b. a rotary casing mounted for rotation in said housing in a predetermined direction about said axis; c. said casing having a radially central inlet and a radially central outlet; d. inlet means for delivering a liquid containing undesirable heavier materials to said inlet; e. outlet means carried by and leading to the exterior of said housing and communicating with said outlet for receiving cleaned liquid; f. baffles in said casing and dividing said casing into circumferentially spaced compartments; and g. the peripheral wall of said casing having passage means communicating with said compartments and said housing of a size to permit passage of heavier particles in the liquid, anD some of the liquid, outwardly into said housing while causing at least a substantial portion of the liquid to be discharged from said casing through said outlet, said passage means including an annular collecting chamber in said peripheral wall of said casing between the inner and outer peripheries thereof, orifices respectively connecting said compartments to said collecting chamber, and tangential nozzles carried by said casing on the outer periphery thereof and facing rearwardly relative to the direction of rotation of said casing and communicating with said collecting chamber, said orifices extending generally rearwardly from said compartments to said collecting chamber with respect to the direction of rotation of said casing.
 2. In a centrifugal separator for a liquid containing undesirable heavier materials, the combination of: a. an outer housing providing an axis; b. a rotary casing mounted for rotation in said housing in a predetermined direction about said axis; c. said casing having a radially central inlet in one side thereof and a radially central outlet in the other; d. inlet means in said housing for delivering a liquid containing undesirable heavier materials to said inlet; e. outlet means carried by and leading to the exterior of said housing and communicating with said outlet for receiving cleaned liquid; f. a substantially axially central partition in said casing perpendicular to said axis and separating said inlet and said outlet; g. the outer periphery of said partition being spaced radially inwardly from the inner periphery of said casing; h. radial baffles in said casing on both sides of said partition and extending axially from said partition to the respective sides of said casing; i. said baffles extending radially from central regions of said casing to the inner periphery thereof to divide said casing into circumferentially spaced compartments; and j. the peripheral wall of said casing having passage means communicating with said compartments and said housing of a size to permit passage of heavier particles in the liquid, and some of the liquid, outwardly into said housing while causing at least a substantial portion of the liquid to be discharged from said casing through said outlet, said passage means including an annular collecting chamber in said peripheral wall of said casing between the inner and outer peripheries thereof, orifices respectively connecting said compartment to said collecting chamber, and tangential nozzles carried by said casing on the outer periphery thereof and facing rearwardly relative to the direction of rotation of said casing and communicating with said collecting chamber, said orifices extending generally rearwardly from said compartments to said collecting chamber with respect to the direction of rotation of said casing.
 3. A centrifugal separator as set forth in claim 2 wherein the smallest transverse dimension of said orifices is less than the smallest transverse dimension of said nozzles.
 4. A centrifugal separator according to claim 3 wherein the total cross sectional area of said orifices exceeds the total cross sectional area of said nozzles by a ratio of the order of at least two to one. 